How to identify if your service is single-phase or three-phase

Short answer

There are three places where you can figure out, in 2 minutes, whether your house is single-phase or three-phase:

1. The switchboard in your house — fastest check.
2. The electricity meter — voltage label.
3. A call to your grid operator — for an official confirmation.

If you also want to understand why this matters (for solar PV, heat pumps, etc.), see Single-phase vs three-phase.

Method 1: the switchboard (30 seconds)

Open the switchboard in your hallway/entrance. Look at the main breaker (the largest one, usually at the top, with the highest amp rating).

• One single big breaker, with one lever (a single "wide module") → single-phase.
• Three breakers ganged together, levers tied by a common bar (raise one, all three rise) → three-phase.

The breaker also shows its amperage. Note it (16, 20, 25, 32, 40 A) — it tells you your house's max power draw. On single-phase, your PV limit comes directly from this number (see the table in the mono vs tri article).

Method 2: the electricity meter (1 minute)

The meter is either inside the house or outside on a wall or pole (depends on operator and area). On the label, look for:

• "230 V" or "1x230 V" → single-phase.
• "400 V" or "3x400 V" or "3x230/400 V" → three-phase.

If the label is faded or covered, fall back to method 1 or 3.

Method 3: count the wires (visual, if you can see the overhead drop)

The wire from the street pole to the house. If you can count the conductors (visible on older drops; harder on modern twisted cables):

• 2 wires (live + neutral) → single-phase
• 4 wires (3 phases + neutral) → three-phase

On modern twisted cables (one thick cable bundling several conductors together), this is harder to read — use method 1 or 2.

Method 4: call the grid operator (official, 5 minutes)

If you want a written confirmation (e.g. for your solar PV file), call your distribution operator and ask for the connection type:

Operator	Phone	Site
E-Distribuție (Bucharest + Banat + Dobrogea)	0800 070 555	edistributie.com
Distribuție Energie Oltenia (Oltenia)	0800 800 545	distributieoltenia.ro
Delgaz Grid (Moldova)	0800 800 928	delgaz-grid.ro
DEER (Transylvania + Northern Wallachia)	0800 800 100	distributie-energie.ro

You'll need your consumption point code (NLC) — printed on every electricity bill, a 7–10-digit number. With the NLC the operator officially confirms your connection type, approved capacity, and main breaker rating.

All operators also have online forms — request "connection information" or "duplicate technical approval (ATR)."

If you don't know which operator you have

• On the bill, look for "operatorul de distribuție" or "OD" — that's the distribution operator (NOT the supplier; the supplier is the brand you pay, e.g. Hidroelectrica, Enel Energie, CEZ Vânzare, etc.).
• The ANRE map (anre.ro) shows operator coverage — each county has exactly one low-voltage distribution operator.

Operators by region (rough; verify on your bill):

• E-Distribuție: Bucharest, Ilfov, Constanța, Tulcea, Timiș, Arad, Caraș-Severin
• Distribuție Energie Oltenia: Dolj, Olt, Vâlcea, Gorj, Mehedinți, Argeș, Teleorman
• Delgaz Grid: Iași, Botoșani, Suceava, Neamț, Bacău, Vaslui, Galați (partly)
• DEER: Cluj, Brașov, Sibiu, Mureș, Alba, Bihor, Maramureș, Hunedoara, Bistrița, Sălaj, Satu Mare, Harghita, Covasna, Prahova, Dâmbovița, Buzău, Vrancea (among others)

Doesn't the bill say it directly?

No, the bill doesn't print "single-phase" or "three-phase" explicitly. But it does include:

• the consumption point code (NLC) — use it to call the operator,
• approved capacity (kW or A) — a hint: "amperaj contor 25 A" usually means single-phase; "3x25 A" or "3x32 A" is clearly three-phase,
• the supplier (the brand you pay) — different from the operator.

Why it matters

Mostly in two scenarios:

• Solar PV — single-phase caps you at 6–9 kW; above that you need an upgrade. See Single-phase vs three-phase.
• New equipment — large heat pumps (>10 kW thermal), fast EV chargers (11+ kW), workshops with machine tools all want three-phase.

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